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Synthesis of ZnO nanoparticles by Ball-milling process for biological applications
(2021-01-01)
Wirunchit, S.
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Gansa, P.
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Koetniyom, W.
This research is focus on synthesis of ZnO nanoparticles (ZnO-NPs) for biological application by Ball-milling process. This research presents the synthesis of ZnO nanoparticles with the difference calcined temperatures ranging from 400 to 900 °C effect on size and morphology. The synthesis ZnO nanoparticles were characterized by employing technique including X-ray diffraction technique (XRD), Fourier Transform Infrared spectroscopy (FT-IR) and Raman spectroscopy. The morphology and size of ZnO nanoparticles determined by Field Emission Scanning Electron Microscope (FE-SEM) and finally studied the effect of antibacterial activity of ZnO NPs. It was found that the temperature at which high purity ZnO is = 800 °C. Especially, at 800 °C, the smallest particle size of ZnO nanoparticles was obtained. The morphology of ZnO nanoparticles from Ball-milling process is spherical. Bacteriological properties of ZnO nanoparticles were found that the synthesis by using the Ball-milling process was high effective to inhibit bacteria.
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Study of nano Titanium (IV) oxide for Self-cleaning applications
(2021-01-01)
Koetniyom, W.
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Bandansong, T.
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Rangkasikorn, A.
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Wirunchit, S.
This research is study the fabrication of a composite film between Polydimethylsiloxane (PDMS) and Titanium (IV) oxide nanoparticles for self-cleaning applications via the spin coating process. This study has focused on the optimum ratio between PDMS and Titanium (IV) oxide and the optimum speed for the spin coating process, especially in order to obtain a composite film with outstanding self-cleaning surface properties. After that, the prepared composite films were studied by UV-Vis spectrometer, water contact angle measurement and solar simulator. Self-cleaning properties was investigated from the testing of wetting properties and measuring the water contact angle. Furthermore, the organic degradation properties were examined by degradation of methylene blue under UV light via solar. From this research was found that the PDMS/Titanium oxide (IV) at 4:3 ratio is the most optimum condition for the fabrication of a composite film by observing with the degradation of methylene blue has showed the highest the degradable efficiency is 55.59%.
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The study of UV protection materials
(2018-09-05)
Wirunchit, S.
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Apivitcholchat, C.
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Chodjarusawad, T.
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Koetniyom, W.
Most people are aware of how harmful UV radiation is to the skin. The sun's ultraviolet rays, UVA and UVB, are known to cause skin damage, from freckling and moles to fatal skin cancer. That's why it is important to apply sunscreen products to your skin, to help you stay sun safe and absorber harmful ultraviolet rays. This research is studied to focus on how to make UV materials to protect UV radiation. The UV absorber additive materials are 4 types; nanoZnO solid powder at size 25-50 nm (ZnO-1), nanoZnO 40%wt in ethanol solution (ZnO-2), nano TiO<inf>2</inf> solid powder at size 17-50 nm (TiO<inf>2</inf>-1) and nano TiO<inf>2</inf> solid powder 325 mesh (TiO<inf>2</inf>-2) respectively, that was mixed in pure baby lotion cream. Three concentration of UV absorber additive materials are 5, 10 and 15 % by weight were compared with pure baby lotion cream. All compositions were tested UV absorbance with UV spectroscopy together with studied micro structure of UV absorber additive materials by Field emission scanning electron microscope (FE-SEM). The techniques to confirm UV absorber materials are X-ray diffraction (XRD), Raman and Fourier transform infrared (FT-IR) spectroscopy. From these results were shown the uncertainty of each concentration of UV absorber materials because of the most of the films were not uniform dispersion and depended on the coating technique. This study evaluated the performance of ultraviolet transmission on of different materials by using a single energy light emitting diode as light source. Titanium dioxide (TiO<inf>2</inf>) and zinc oxide (ZnO) are two of most popular inorganic ultraviolet protective materials in UV protection skin care products was studied.
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Phase formation polycrystalline vanadium oxide via thermal annealing process under controlled nitrogen pressure
(2017-10-20)
Jessadaluk, S.
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Khemasiri, N.
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Rahong, S.
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Rangkasikorn, A.
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Kayunkid, N.
This article provides an approach to improve and control crystal phases of the sputtering vanadium oxide (V<inf>x</inf>O<inf>y</inf>) thin films by post-thermal annealing process. Usually, as-deposited V<inf>x</inf>O<inf>y</inf> thin films at room temperature are amorphous phase: post-thermal annealing processes (400 °C, 2 hrs) under the various nitrogen (N<inf>2</inf>) pressures are applied to improve and control the crystal phase of V<inf>x</inf>O<inf>y</inf> thin films. The crystallinity of V<inf>x</inf>O<inf>y</inf> thin films changes from amorphous to α-V<inf>2</inf>O<inf>5</inf> phase or V<inf>9</inf>O<inf>17</inf> polycrystalline, which depend on the pressure of N<inf>2</inf> carrier during annealing process. Moreover, the electrical resistivity of the V<inf>x</inf>O<inf>y</inf> thin films decrease from 105 Ω cm (amorphous) to 6×10-1 Ω cm (V<inf>9</inf>O<inf>17</inf>). Base on the results, our study show a simply method to improve and control phase formation of V<inf>x</inf>O<inf>y</inf> thin films<inf>.</inf>
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Control the crystal growth of Al-doped ZnO thin film prepared by pulsed laser deposition and the influences on its optical and electrical properties
(2017-10-20)
Khemasiri, N.
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Jessadaluk, S.
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Kayunkid, N.
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Rahong, S.
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Rangkasikorn, A.
In this work, highly transparent and highly conductive thin films of Al-doped ZnO (AZO) are achieved by pulsed laser deposition (PLD). By changing substrate temperature in the range of room temperature to 500°C during the deposition process, the preferential growth direction of AZO crystal is controlled and, therefore, the surface morphology, optical and electrical properties of AZO thin films are able to be manipulated. X-ray diffractograms as a function of the substrate temperature clearly illustrate the ability to control the preferential growth direction of AZO. At the low substrate temperature, the growth along [002] direction corresponding to c-axis of hexagonal ZnO is only observed. By elevating the substrate temperature, not only crystallinity of AZO thin film is further improved but also the competition of crystal growth along the [002], [001] and [101] directions are occurred due to the increase of total energy and surface mobility of cluster/atom. The AZO films obtained by all preparation conditions exhibit an n-type semiconducting characteristics, furthermore, the carrier concentration and the carrier mobility of AZO thin films can be optimized to reach 4.10×1020 cm-3 and 7.53 cm2/Vs, respectively. The excellences in both carrier concentration and mobility of AZO thin film lead to very low resistivity of 2.08×10-3 cm. In addition, the wide optical band gap of ∼3.50 eV together with the high transparency over 90% in visible region is obtained from the AZO thin films. The exceptional optical and electrical properties of AZO thin film demonstrate that such material has enough potential to become a promising candidate using in optoelectronic applications.
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Improved Efficiency of Polymer Solar Cells by means of Coating Hole Transporting Layer as Double Layer Deposition
(2017-10-20)
Chonsut, T.
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Kayunkid, N.
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Rahong, S.
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Rangkasikorn, A.
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Wirunchit, S.
Polymer solar cells is one of the promising technologies that gain tremendous attentions in the field of renewable energy. Optimization of thickness for each layer is an important factor determining the efficiency of the solar cells. In this work, the optimum thickness of Poly(3,4-ethylenedioxythione): poly(styrenesulfonate) (PEDOT:PSS), a famous polymer widely used as hole transporting layer in polymer solar cells, is determined through the analyzing of device's photovoltaic parameters, e.g. short circuit current density (J<inf>sc</inf>), open circuit voltage (V<inf>oc</inf>), fill factor (FF) as well as power conversion efficiency (PCE). The solar cells were prepared with multilayer of ITO/PEDOT:PSS/PCDTBT:PC<inf>70</inf>BM/TiO<inf>x</inf>/Al by rapid convective deposition. In such preparation technique, the thickness of the thin film is controlled by the deposition speed. The faster deposition speed is used, the thicker film is obtained. Furthermore, double layer deposition of PEDOT:PSS was introduced as an approach to improve solar cell efficiency. The results obviously reveal that, with the increase of PEDOT:PSS thickness, the increments of J<inf>sc</inf> and FF play the important role to improve PCE from 3.21% to 4.03%. Interestingly, using double layer deposition of PEDOT:PSS shows the ability to enhance the performance of the solar cells to 6.12% under simulated AM 1.5G illumination of 100 mW/cm2.
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Rapid convective deposition; An alternative method to prepare organic thin film in scale of nanometer
(2017-01-01)
Chonsut, T.
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Rangkasikorn, A.
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Wirunchit, S.
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Kaewprajak, A.
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Kumnorkaew, P.
The aim of this research is to introduce the alternative process named "Rapid Convective Deposition" to obtain organic thin film in nanometer scale. There are several advantages of this method, including simply control film thickness via solution concentration and translational speed as well as significantly reduce required material leading to lower manufacturing cost. The specific properties of thin film were characterized by the combinations of microscopic and spectroscopic techniques. To confirm that the convective deposition has a potential to become a candidate method using to prepare thin film, the films prepared by conventional spin coating and alternative convective deposition were compared in term of processing e.g. required solution as well as processing time and film's properties e.g. thickness, morphology and uniformity of the film. The results indicate that the rapid convective deposition is able to provide similar film's quality as obtain from spin coating but requires less processing time and required solution to prepare the nanoscale organic thin film.
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High temperature phases in the 0.98 PbZrO3 -0.02Pb (Ni 1/3Nb2/3) O3 ceramic
(2009-07-09)
Qu, W.
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Tan, X.
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Vittayakorn, N.
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Wirunchit, S.
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Besser, M. F.
The phase evolution with temperature in the 0.98 PbZrO<inf>3</inf> -0.02Pb (Ni<inf>1/3</inf>Nb<inf>2/3</inf>) O<inf>3</inf> ceramic was investigated with dielectric permittivity and polarization measurements, hot stage transmission electron microscopy, and high temperature x-ray diffraction. Below 190 °C, the ceramic is in the antiferroelectric phase with characteristic 1 4 { 110 } c superlattice diffractions. In this stage, typical antiferroelectric 180° domains were observed. Between 190 and 220 °C, an intermediate phase, which is characterized by 1 2 { 110 } c -type superlattice diffractions, was detected. Evidences are found to suggest that this intermediate phase is ferroelectric. The 1 2 { 110 } c -type superlattice diffraction persists even into the paraelectric phase above 220 °C. In addition, there exists an incommensurate phase between the low temperature antiferroelectric phase and the intermediate ferroelectric phase. © 2009 American Institute of Physics.
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Structural transformation in antiferroelectric PbZrO3-relaxor ferroelectric Pb(Ni1/3 Nb2/3)O3 solid solution system
(2008-08-12)
Wirunchit, S.
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Vittayakorn, N.
The solid solution between the antiferroelectric (AFE) PbZrO<inf>3</inf> (PZ) and the relaxor ferroelectric (FE) Pb (Ni<inf>1/3</inf>Nb <inf>2/3</inf>)O<inf>3</inf> (PNN) was synthesized by the columbite precursor method. The crystal structure, phase transformations, and dielectric and thermal properties of (1-x) PZ-xPNN where x=0.00-0.30 were investigated. With these data, the FE phase diagram between PZ and PNN has been established. The crystal structure data obtained from X-ray diffraction indicate that the solid solution PZ-PNN, where x=0.00-0.30, successively transforms from orthorhombic to rhombohedral symmetry with an increase in the PNN concentration. The AFE phase→FE phase transition occurs in compositions of 0.00≤x≤0.08. The AFE→FE phase transition shifts to lower temperatures with higher compositions of x. The FE phase temperature range width increases with increased PNN. Apparently the replacement of the Zr4+ ion by Ni 2+/Nb5+ ions decreases the driving force for an antiparallel shift of Pb2+ ions because they interrupt the translational symmetry and facilitates the appearance of a rhombohedral FE phase when the amount of PNN is higher than 8 mol %. © 2008 American Institute of Physics.
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Effect of lead nickel niobate substitution on phase transitions of lead zirconate ceramics prepared by the solid state reaction method
(2008-01-01)
Wirunchit, S.
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Laoratanakul, P.
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Vittayakorn, N.
The solid solution between the antiferroelectric, PbZrO<inf>3</inf> (PZ), and relaxor ferroelectric, Pb(Ni<inf>1/3</inf>Nb<inf>2/3</inf>)O<inf>3</inf> (PNN), was synthesized by the columbite method. The phase structure and phase transition of Pb(Zn<inf>1-X</inf>(Ni<inf>1/3</inf>Nb<inf>2/3</inf>) <inf>x</inf>O<inf>3</inf> (PZNN), where x = 0.0 ≤ x ≤ 0.50, were investigated. The samples were kept at the calcination temperature of 900°C for 4 h and at the sintering temperature of 1,150°C for 2 h. Phase formation and phase transition of PZNN were investigated by x-ray diffraction (XRD) and thermal analysis, respectively. It was found that the structure of sintered pellets is orthorhombic for 0.0 ≤ x ≤ 0.10, rhombohedral for 0.20 ≤ x ≤ 0.30 and pseudo-cubic for x = 0.5. DSC measurement shows that in the antiferroelectric (AFE) phase - ferroelectric (FE) phase and FE to paraelectric (PE) phase; phase transformation temperatures decrease with increasing PNN concentration. The AFE-FE phase transformation was detected for compositions 0.00 ≤x≤ 0.08. © 2008 Trans Tech Publications, Switzerland.

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